This invention relates to appartus in which conveyors transport materials through a liquid bath having two different temperature zones separated by a slotted wall. More particularly, the invention involves means for promoting the flow of liquid from one temperature zone through the slotted wall to the other zone.
U.S. Pat. No. 4,522,217 to D'Alterio shows in FIG. 4 a commercially successful form of liquid bath having two temperature zones in which a pair of continuous conveyor belts transport a pasta product through a zone of boiling water and through a slotted wall into and through a zone of cold water.
U.S. Pat. No. 2,286,644 to Pringle et al illustrates in FIG. 1 another apparatus in which conveyor belts carry potato slices through a cooking vat containing vegetable oil and having a slotted wall for the passage of the conveyor belts therethrough. The slotted wall thus permits the maintenance of different temperatures in the oil on its opposite sides.
In all such systems wherein a substantial temperature difference is desired in the zones of the liquid bath which are on opposite sides of a slotted wall, it is difficult to prevent the temperature of the liquid bath in the vicinity of the slot from being at some level intermediate the two desired zone temperatures. The aforesaid patent of D'Alterio discloses steam chests and containers filled with insulation adjacent the slot and on opposite sides of the wall in the liquid bath to minimize the amount of liquid bath which is not at either of the two desired zone temperatures. The suggested means for minimizing intermediate temperture near the slot are helpful but cumbersome both structurally and operationally.
A principal object of this invention is to provide simple and effective means for minimizing the amount or portion of liquid at less than desired temperature near the slot in a wall which divides a liquid bath into zones of different temperatures.
Another important object is to provide means for more positive control of liquid flow in the desired direction through the slotted wall in a liquid bath divided thereby into two different temperature zones.
A further important object is to provide means to scour the product on the conveyor passing through the slotted wall to loosen and remove undesirable matter from the product treated in the liquid bath.
These and other features and advantages of the invention will be apparent from the description which follows.